1. Field of the Invention
The present invention primarily relates to a relay server that enables communication between terminals.
2. Description of the Related Art
A communication technique referred to as a Virtual Private Network (VPN) is conventionally known. The VPN is used, for example, for communication over the Internet between terminals connected to a Local Area Network (LAN) of a plurality of branch offices (base points) established in multiple regions. Through the use of the VPN, another LAN in a remote location can be used as if it is a directly connected network.
However, since a system of the above-described type establishes the network virtually, the system tends to be rigid. Therefore, it is not easy to establish a scalable and flexible system. For example, in a conventional communication system, a terminal capable of exchanging data between base points and a terminal incapable of such exchange cannot be selectively set at each base point.
Moreover, when a resource, such as a file, is shared with a base point in a remote location, the base point in the remote location may mishandle the file, causing unintended alteration and/or loss of the file.
In order to prevent such erroneous operations due to mishandling of the file, a method of locking the file with a password, for example, can be used. However, this method can be used only when a file in a file format that can be locked with a password is shared, and a simple text file, for example, cannot be locked with a password. Accordingly, the unintended alteration and/or loss of the file cannot be prevented in all cases.